Odd Parasitic Draw

I have a '96 GLX (yes I know, its not a diesel but it will be soon) that has been having a troublesome battery drain issue over the last few weeks. I have a 6 month old Optima Redtop installed that is tested good and my alternator is putting out the necessary 14.xx volts when the car is running. I even installed my spare battery from another car and it still had the draw so at this point I am convinced I am not having a battery issue but rather a wiring issue.

The draw will consistently pull about .02/.03 volts per hour from the battery, even with every fuse and relay pulled. Initially I suspected the stock radio may be at fault so I unplugged that but it did nothing to lessen the drain.

Does anyone know of any other relays or control modules that could be drawing power with all of the lower 22 fuses removed? I have a hunch that it may be the alarm control module as that caused some issues in my A3 a few years ago but I have yet to test that theory. I've heard of chaffed wires in the door boots could attribute to these issues but I have yet to see any upon inspecting the boots.

Any help would be greatly appreciated

RED TOP? geese you got money to blow lol. What is the mA (milli amp) draw?pull boots on all doors and inspect wires. be careful they will be brittle. get your multimeter and check each fuse for a draw, there are good youtube videos on how to do this. its a bit involved but it would be a dome light or a door switch, to a wire issue in the door. any codes with VCDS? sometimes you can find it that way. hard to tell with out more information. start with the doors, then go to the lights and switches.

I am having this with mine, it draws .03-.04 amp, and I couldn't find any fuse that would stop it. I haven't tried all of the relays yet. There are a couple of fuses under the hood. I was thinking of checking the one to the cooling fan, because that has to come on with the ignition off. I have to double check my stereo setup, it is an sony, installed poorly.

the relay controller for the fans in under the coolant tank. pull the fuse from that, and test. any issues with the fans? is the clear cap missing from it? its a common failure and can cause a draw easily

I haven't heard the fans come on yet, they spin freely, I guess I will have to test them...and try pulling the relay and see if the power draw drops.

they will come on or off with out reason. if they stick on tap the controller with a wrench and that will free up the relay temporarily. if the cap is in good shape nad your issues dont change by pulling that 20 amp fuse than its good.

Mongler98 said:

they will come on or off with out reason. if they stick on tap the controller with a wrench and that will free up the relay temporarily. if the cap is in good shape nad your issues dont change by pulling that 20 amp fuse than its good.

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Nothing on these cars happens without reason.

I have found chafed wires for the cooling fans, still wrapped in the original harness, just behind the drivers headlight. With the age these have on them it's not uncommon for the vibrations to crack the insulation and cause problems.

But, it's fairly easy to trace down the affected circuits (just time consuming) by disconnecting the wires one at a time while the car is at 'rest' and check for amperage draw. Don't check for volts because it won't tell you much. The ammeter must be in series with the circuit to test for amperage. So you remove an individual wire and connect one multi tester lead to it, the the other to where the wire was previously connected. Record the values so you can keep track. A few circuits will always pull minor amperage, so don't be alarmed if you find one. Just identify it to see whether it should have a draw in the resting state.

I've found chafed wires, bad ignition switches, hack job additions, and burned components all cause similar parasitic draw problems.

Good luck with your search. If you have access to a Bentley manual, this is when it becomes invaluable.

Here is a better way to do a draw test:

https://humblemechanic.com/best-way-perform-parasitic-draw-test/

Once you isolate the circuit with the draw, then you need to look at the wiring diagram and unplug the components down stream from the fuse. You do this one a time, once the draw goes away, then you know what to replace. Good luck!